Halogen acyl alkyl pentoses



Patented Mar. 18, 1941 5 PATENT OFFI W 2,235,189: 3 it HALOGEN ACYLALIWL PENTOSE$ t d V. White, Moscowfldaho, assignor to- The Dow ChemicalCompany, Midland, Mich, a corporation of Michigan No Drawing.Application September 13, 1939,

Serial No. 294,687

6 Claims.

This invention relates to halogen acyl alkyl pentoses having the generalformula pentose obtained has bromine in the 1 position, an ethyl groupin one of the 2 or 3 positions, an acetyl group in the 4 position andone in whichever of the 2 or 3 positionsis unoccupied by the 5 ethylgroups. The formulas are represented thus 5 wherein X is chlorine orbromine, one B. is an alkyl radical, the other R is alkyl or acyl, and Ris an acyl radical. The pentose may be 0CrHt exylose, arabinose, orother compound having O O the indicated structure. 0450K Compoundshaving the formula given above are useful as intermediates in thepreparation U m 3 f i m of new ethers and ether esters of pentoseglycolace y y 058 r sides adapted for use as plasticizers for carbolhydrate ethers and esters. The new halogen acyl o alkyl pentoses may beprepared in a manner to LB assure the desired structural configurationby reacting upon alkyl ethers of hemi-cellulose or H1CCH1 CH 0 thecorresponding ethers of other pentosans with n- OC:CH3

an acyl halide or other acylating-halogenating H20 20 agent, such as asolution of the hydrogen halide in an anhydrous lower fatty acid orlower fatty z-l'dificetyl s'ethyl acid anhydride. For example, ethylhemi-cellu- The invention has been illustrated with respect lose reactswith acetyl bromide-acetic acid mixto bromo acetyl ethyl pentosesprepared from ture to give l-bromoacetyl ethyl pentose, whereethylethers of hemi-cellulose. Similar comin the ethyl group is in at leastone of the 2 or 3 pounds, within the scope of the invention, maypositions, the acetyl group is in the 4 position, be prepared from otherethers of helm-cellulose and all hydroxyl groups in the pentose productor other ethers of pentosans, such, for example, are substituted eitherby the ethyl or the acetyl as the propyl, butyl, or lauryl ethers of thepengroups. tosans. Combined acylating and halogenating 30 The followingex p a es the practice agents other than acetyl bromide may also be ofthe invention: used. To illustrate, acetyl chloride, propionyl 50 gramsof fully ethylated hemi-cellulose (2 chloride or bromide, or butyrylchloride or broethyl group p r pentose unit) is added portionmide may beused suitably in solution in the corwise to a mixture of 150 cc. ofglacial acetic responding fatty acid or mixture thereof with 35 acid and30 ccof a yl mide at a t mp rathe fatty acid anhydride. Instead of theacyl ture 0f about 8--10 C. The reaction mixture is haflide, there maybe used a solution of hydro- Set aside in a refrigerator i a DP fl genchloride or hydrogen bromide in acetic acid, for 6 hours at atemperature of Q The or equivalent fatty acid, suitably in the presence10 mixture is diluted with about 3 volumes of ethyl of the fatty acidanhydride. 40 ether, and poured into ice water. The ether lay- The newcompounds decompose when heated er is washed with several successiveportions of or when exposed t fight, and are preferably ice Water to reme ace acid and hydmgen ployed in solution soon after their preparation.bromide. The bro O ty ethyl XYIOSB remains If necessary to keep them foruse at a later time,

in the ether solution which is then clarified with they may be Stored ina m place suitably in 45 charcoal, filtered, d drie Analysis shows thesolution in ethyl ether or like inert solvent in a product to contain25.5 per cent Of bromine, COF- dark glass container. They are allreadily responding los y to a Product Of the formula active with metalphenolates or with primary alcohols in alkaline medium to produce newglycosidic compounds as described in co-pending ap- 50 plication, SerialNo, 294,688, filed concurrently herewith. 113C CHr-O-C-H O 0 We claim:

1. A compound having the general formula 11 -O-CCH3 0 55 1b 4 :2 ml 105XH-OHOR-CHORCHOR-ll1 mm? m y m y xy 6 wherein one B is an alkyl radical,the other R is When partially alkylated h L u is selected from the groupconsisting of allsyl raditreated in like manner, the bromo acetyl ethylCalls and acyl radlcals: 15 an acyl Tadlcal and 60 X is one of thehalogens bromine and chlorine. 6. A bromc acetyl ethyl pentose havingthe for- 2. A compound having the general formula mula set forth inclaim 1, wherein at least one of the o radicals R is an ethyl group. i fi 5 3. A compound having the general formula set r HCHORCHORCH(OOCHQ) H2forth in claim 1, wherein the acyl radical is acetyl. wherein one of theradicals R is ethyl and t A p d having the general formula Set otherradical R is selected from the group conforth in claim 1, wherein thehalogen is bromine. sjstjng of the ethyl and acetyl rad1ca1s 5. l-bromo4-acety1 2.3-diethyl exylose. ELWOOD WHITE

